Electric motor drive for sewing machines



Nov. 11, 1952 Wl 1 PEE-rs 2,617,375

ELECTRIC MOTOR DRIVE FOR SEWING MACHINES Filed sept. 17. 1947 3 sheets-sheet 1 NIT S Q Q @1 .E mm Y wn i{i @l R0. n EEN Kun, nd W J wm m6. E R E mm NS ww E RS EN R M N WQ M \.l|,\\ x) R @m s m om QQ S EN. G s w Nm; ZHIA l ,L.... l I l l l v l I l l l v r a, d mm mm mh @Nw l! km E @n v w E ,Y QM E E N *Y Y Y.

Nov. 11, 1952 w. J. PEETs 2,617,375

ELECTRIC MOTOR DRIVE F' OR SEWING MACHINES Filed Sept. 17. 1947 3 Sheets-Sheet 2 INVENToIa. Wilbur JPeeZs WITNESS. BY

(MJ www Nov. 11,

w. J. PEETs 2,617,375 ELECTRIC MOTOR DRIVE FOR SEWING MACHINES Filed sept. 17, 1947 3 Sheets-Sheet 3 litt?.

NI/ENTOR' A TTR/VEX Patented Nov. 11, 1952 ELECTRIC MOTOR DRIVE FR SEWING MACHINES Wilbur J. Poets, Elizabeth, N. J., assigner to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application September 17, 1947, Serial No. 774,597

6 Claims.

This invention relates to driving means for sewing machines and more particularly to electric motor driving means housed in the frame of a family-type sewing machine.

An object of the invention is to provide an improved sewing machine and motor drive unit construction.

A specific object of the invention is to provide improved means for mounting an electric motor in the bracket-arm standard of a family-type sewing machine; the motor being completely housed within and insulated from the sewing machine frame.

With the above and other objects in View, as will hereinafter appear, the invention comprises the devices, combinations, and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

Fig. 1 is a front elevational View of a sewing machine embodying the invention, portions being broken away to show certain operating parts and their supports;

Fig. 2 is a view taken substantially on the line 2-2 of Fig. l and looking in the direction of the arrows;

Fig. 3 is a fragmentary bottom plan view of the sewing machine shown in Figs. l and 2, the bottom cover having been removed;

Fig. 4 is a fragmentary sectional view taken on the line te-ll of Fig. 1; and

Fig. 5 is a fragmentary sectional View along the line 5--5 of Fig. 2,

As illustrated in the drawings, the frame of the sewing machine comprises a substantially rectangularly shaped bed-plate or base i l, for l.- ing on its upper side a work-supporting plate and provided on its under face with a plurality of transversely and longitudinally arranged strengthening ribs l2, downwardly extending side-walls I3 and end walls, as it, forming a boxlilze enclosure, the downwardly facing opening of which is normally closed by a bottom cover plate it held in place by a washer il and nut I3; the latter being threaded on a stud i@ extending downwardly from the under face of the base I I,

Suitably secured upon the hollow bed il is a vertically disposed hollow standard 2| which carries an overhanging bracket-arm 2?. terminating in a hollow head 23 in which is mounted the usual reciprocatory needle-bar 2t and presser-bar 26. The upper part of the bracket-arm 22 is closed by a cover-plate 27 held in place by screws, as 28. A main driving shaft 29, disposed within and lengthwise of the overhanging bracket-arm 22, is journaled in bearings of which one is shown at 3l. The arm-standard end of the shaft 2Q carries a sleeve 32 secured thereto by a screw S3. A hub-extension S4 of a hand-wheel 3% is rotatably mounted on this sleeve 32. A 1aminated impregnated-fabric driven gear 31 is freely mounted on the hub-extension 34 and is held against longitudinal movement by a split spring-ring 33 and a flange 3B of the hub 34. The gear 3i is shrouded by a pair of spaced rings lll held together by rivets ft2. rlhe gear 3l, in a manner similar to that shown and described in Patent No. 1,934,373, issued November '7, 1933, has a pin (not shown) projecting from one side face thereof. This pin (not shown) is connected by a circular spring i3 with a pin ifi carried by the flange 3d. The sleeve 32, in a manner similar to that shown in Patent No. 1,934,373, is formed with a shoulder it against which an end of the hub-extension 3&2 is clamped by a manually operated clutch screw fil. The clutchscrew is threaded into the outer end of the sleeve S2 and, in cooperation with a washer t3, having tongues which enter keying notches in the sleeve 32, functions to connect the shaft 29 to the driven n hand wheel 35T.

rIhe main shaft 2g, in a well known manner, drives the needle-bar 2li carried in the head 23. A loop-taker actuating shaft 52, journaled in the base El, is driven by the main shaft 29 through bevel gears 53 and 5d, vertical shaft Eli and bevel gears El and A pair of actuating eccentrics El and E2 are formed integral with the gear 53 and the combination is held in place by a set screw 63. The eccentrics 6l and 62 actuate pitmans 64 and 65 respectively and these in turn actuate rock shafts 5l and $3 which impart the usual feeding movements to a feed dog 69.

The arm-standard 2| is especially designed to provide adequate space for housing sewing machine parts. To this end, the arm-standard is made in substantially the shape of a pyramid, the lower portion of the standard being larger than the upper portion. A back portion 'il of the standard 2l has an enlarged offset portion l2 (Figs. 2, 4) and this ofset portion, together with the otherwise enlarged pyramidal base of the standard provides space for housing a vertically disposed electric motor i3.

The right side 'ifi (Fig. l) of the arm-standard 2l has an aperture it arranged to receive a flushtype, three-pin terminal Ti. A two-conductor electric cord 'i3 connects the two outer contacts of the terminal 'il to a lamp socket 79, having a switch 8d and carrying a lamp bulb 8|; the latter being protected by a shield S2. riwo electrical conductors 83, housed entirely within the machine frame, connect the central contact and one of the outer contacts of the terminal Tl, to a pair of contacts 84 carried by the motor '13. Each of the motor contacts S4 is covered with an insulating nut 86.

The electric motor 'I3 has alower .enclosing frame member or end-bonnet 93 made from a non-conducting plastic, whereas an upper enclosing frame member or end-bonnet 9d is made from aluminum; the two being joined on a, horizontal line indicated by the numeral 96. Both of the frame members have opposed flattened sides 9`| and 98, thus making it possible to install the motor in a small space. The lower member 93 has an integrally formed terminal box 99 which supports the downwardly disposed contacts ad. The upper portion 94 has a lug II (Fig. 2) which has a threaded hole IDI) that is parallel to the axis of the motor T3. The upper portion 95| is formed'with a four-armed spider IZ that supports a concentric upstanding, hollow, tubular stem w3 through which extends and by means of a bearing (not shown) rotatably supports an elongated motor shaft lld. The external surface (Fig. 2) of the stem |63 is shouldered to form a lower cylindrical neck It which carries a cylindrical insulating bushing IIB'I, a reduced intermediate and upwardly tapered portion |98, and an upper and further reduced cylindrical neck |09 which carries a cylindrical insulating bushing III of a diameter slightly less than the outer diameter of the lower bushing lill. An armature I I is rotatably supported in the motor frame on the shaft |04 and the upper end of said shaft carries an elongated worm IIE held thereto by a set screw I I3.

Internally of the arm-standard 2 I, there is provided a vertically disposed cylindrical recess or well IIII partly formed byV a segmental wall II5. The well is formed to provide an upper cylindrical surface III of reduced diameter, an intermediate enlarged surface IIl, and a still further `enlarged lower cylindrical surface I I8; the upper and lower cylindrical surfaces being coaxially arranged, vertically spaced and of such size as respectively to form seats for the upper and `lower cylindrical bushings III and IIl'I carried by the motor stem I. Since the upper and lower surfaces III and IIB, and the bushings III and lill are cylindrical in form, and since the lower surface ||8 and lower bushing IIII are diametrically larger than the upper surface I I6 and upper bushing I I I, there is provided a combination of a motor and a frame into which frame the motor can easily be inserted and from which frame the motor can easily be removed. The surfaces I Ie and II8 and the bushings III and I Ill' are so constructed and arranged that, when the motor 73 is in place, the worm I I2 meshes with the worm gear 31 of the sewing machine drive. This construction necessitates that the upper end of the well IUI be located adjacent the worm gear 3l. Thus, the inner wall of the hollow standard ZI denes a vertically elongated compartment and the well |44 is formed in a secondary wall structure H5 which projects llaterally from the inner wall of the standard and into the confines ofthe standard compartment. Furthermore, the apertured vertical portions of this secondary wall, containing the shaft bushing 3I, forms, with the horizontal portion of the secondary wall, containing the well IIA, a chamber in which is housed the gear wheel 3l and the balance-wheel clutch.

The offset portion l2 of the sewing machine standard is provided (Figs. 2 .and 4) with a radially disposed external recess |22 which carries an insulating insert I23 having a vertically disposed countersunk hole IM. The bottom wall of the recess |22 is Vapertured by an enlargedhole |26 and, when the sewing machine motor'l isA in ioperating position, a single screw I2l passes downwardly through the hole IM, the hole I2, through a, hole in an insulating washer |28, hereinaf ter referred to, and is screwed into the threaded hole Iil of the motor frame member 9d.

Within limits, the relative vertical position of the worm I I2 with respect to the gear El is not critical, and the verticalposition of the motor 'I3 is governed entirely by the axial length of the washer |28, the position of the abutting surface surrounding the lower end of the hole Id and the position of an abutting surface surrounding the upper end of the hole it. v

The motor herein described can be quickly installed in the sewing machine standard and removed therefrom with a minimum of effort. To remove the motor I3 from the sewing machine, an operator removes the thumb nut It and the bottom cover It. Then the conductors 83 are disconnected from the contacts IM. Next the screw I2? is loosened. When the screw ilbecomes completely disengaged from the hole It@ in the upper member 9d, the motor I3 is completely free to be withdrawn from the sewing machine frame.

It will be noted that the motor I3 is completely insulated from the frame of the sewing machine. The two insulating bushings Il and I I I, insulate the stem Iilti of the motor from the sewing machine frame, and the metallic worm II2 is insulated from the sewing machine by the insulating from the sewing machine by the insulating gear 3l'. Furthermore, the insulating insert |23 and the insulating washer m8, together -with enlarged hole |26 insulate the motor from the sewing machine at the point where the twok are held together by the screw IZ'I. Since the lower end frame 93 is made from an insulating material, there is no danger of a person getting a shock from the motor, even when the motor is in place and the lower cover It of the sewing machineis removed for the purpose of making inspection of, or repairs to, other parts of the sewing machine mechanism.

As indicated by the arrow |32 irl Fig. 2, the worm II2 drives the gear 3l in a counterclockwise direction. This creates a downwardly directed component of force in the worm II2 and the shaft Ili. This force and a force caused by the weight of the motor shaft Ilfl, worm |I2, and motor armature III) add to produce a downwardly directed thrust on the bearing which support the shaft Ifl. Since these forces are additive and not subtractive, the possibility of hunting between two forces is eliminated.

Having thus set forth the nature of the invention, what I claim herein is:

1. In a sewing machine having a frame including a base and a bracket-arm having a hollow standard rising from said base and together therewith forming a vertically disposed compartment extending entirely through the bottom of said base; a horizontally disposed upper rotary shaft journaled in and extending lengthwise of said bracket-arm; a horizontally disposed lower rotary shaft journaled in and extending lengthwise of said base; driving connections between said shafts including a shaft vertically disposed in said standard; a vertically apertured supporting wall extending inwardly from the upper portion of said standard into said compartment; and a unitary driving structure disposed in said compartment and spaced horizontally from said driving connections for removal of said structure endwise from said compartment through saidbase, said driving "structure *comprising a vertical-axis electric motor having a frame disposed in the lower portion of said compartment and an upwardly extending reduced frame-portion seated in the vertical aperture of said supporting wall, a vertically disposed motor-shaft journaled in said reduced frame-portion and having its axis of rotation oifset laterally from the horizontal axis of rotation of said upper shaft; intermeshing driving and driven gears carried by said motor shaft and said upper shaft; and means removably securing said driving structure in operative position in said compartment.

2. In a sewing machine having a frame including a horizontally extending hollow base with a vertically disposed hollow standard rising from one end portion of said base, the inner walls of said standard and base together forming a vertically disposed compartment which eX- tends entirely through the bottom of said frame base; an arm projecting laterally from the upper end of said standard; an upper rotary shaft journaled in and extending lengthwise of said arm; a driven gear carried by said upper shaft over said compartment; a lower rotary shaft journaled in and extending lengthwise of said base at one side of the lower end of said compartment; and driving means disposed within and at one side of said compartment and connecting said upper and lower shafts for rotation in a xed timing relationship; the combination therewith of a secondary wall projecting from the inner standard wall and into the confines of said compartment at the junction of said arm and standard, said secondary Wall depending downwardly into said compartment and having a substantially vertically disposed bore running lengthwise therethrough with the length of said bore being substantially greater in dimension than the greatest lateral diameter thereof; a unitary driving structure including an electric motor having a motor casing vertically disposed within the lower portion of said compartment adjacent said driving means, an elongated stem projecting axially from said casing and provided with a peripheral bearing surface complemental in size to the internal wall of said bore with the length of said stem being at least equal to one-half the axial length of the motor casing proper, an elongated motor shaft journaled Within and projecting from the free end of said stem, and a driving gear carried upon the distal end of said motor shaft, said driving structure normally being removably disposed within said compartment with its stem being slidingly received lengthwise of and within said bore; and means carried by said frame for maintaining said stem in mating relation with said bore thereby to position said two gears in mesh.

3. A sewing machine comprising in combination a frame including a horizontally extending hollow base with a vertically disposed hollow standard rising from one end portion of said base, the inner walls of said standard and base together forming a vertically disposed compartment which extends entirely through the bottom of the frame base, and an arm projecting laterally from the upper end of said standard; an upper rotary shaft journaled in and extending lengthwise of said arm; a secondary wall projecting laterally from the inner standard wall and into the confines of said compartment at the junction of said arm and standard, said secondary wall depending downwardly into said compartment and having a substantially vertically disposed and downwardly progressively enlarged bore running lengthwise therethrough with its longitudinal axis horizontally spaced from the longitudinal axis of said upper shaft; a driven wheel gear carried by said upper shaft adjacent the upper end of said bore; a unitary driving structure including an electric motor having a motor casing vertically disposed Within the lower portion of said compartment, an elongated stem projecting axially in a progressively reduced manner from said casing and provided with a peripheral bearing surface complemental in size to the internal wall of said bore but having its greatest lateral dimension substantially less than the smallest lateral dimension of the motor casing, an elongated motor shaft journaled within and projecting from the free end 0f said stem, and a driving worm gear carried upon the distal end of said motor shaft, said driving structure normally being removably disposed within said compartment with its stem being slidingly received lengthwise of and within said bore; means removably to maintain said stem in a mating relation with said bore thereby t0 position said driving and driven gears in mesh; a lower rotary shaft journaled in and extending lengthwise of said base; and driving means disposed within said standard compartment and connecting said upper and lower shafts for rotation in a fixed timing relationship, said lower shaft and said driving means being located entirely at one side of said motor casing so that the unitary driving structure may be inserted into and removed from said compartment by way of said base.

4. In a sewing machine having a frame including a horizontally extending hollow base with a vertically disposed hollow standard rising from one end portion of said base, the inner walls of said standard and base together forming a vertically disposed compartment which extends entirely through the bottom of said frame base; an arm projecting laterally from the upper end of said standard; an upper rotary shaft journaled in and extending lengthwise of said arm; a driven wheel gear carried by said upper shaft over said compartment; a lower rotary shaft journaled in and extending lengthwise of said base at one side of the lower end of said compartment; and driving means disposed within and at one side of said compartment and connecting said upper and lower shafts for rotation in a xed timing relationship; the combination therewith of a secondary wall projecting laterally from the inner standard Wall and into the connes of said compartment at the junction of said arm and standard, said secondary wall depending downwardly into said compartment and having a substantially vertically disposed and downwardly progressively reduced stepped bore running lengthwise therethrough with the length of said bore being substantially greater in dimension than the greatest lateral diameter thereof and with its longitudinal axis being horizontally spaced from the longitudinal axis of said upper shaft; a unitary driving structure including an electric motor having a motor casing vertically disposed within the lower portion of said compartment adjacent said driving means, an elongated stepped stem projecting axially in a progressively reduced manner from said casing and provided with a peripheral bearing surface complemental in size to the internal wall of said bore with the length of said stem being at least equal to onehalf the axial length of the motor casing proper,

an elongated'motor shaft journaled within and projecting from the free end of. said stem,.and a driving worm gear carried upon the distal end of said motor shaft, said driving structure normally being removablyv disposedwithin said compartment withk its stem being slidingly received lengthwiseof and within said bore; and means carried bysaid frame for. maintaining said stem aimating relation with said borethereby'to positionsaid wheel and worm gearsiin' mesh.

5. A sewing machine comprisingin combinae tion aV frame including a horizontallyv extending hollow base with a vertically disposed hollow standard rising from one .end portion of saidbase, the inner walls of said standard and base together forming a vertically disposedv compartment which extends entirely through the bottom of the frame base, and an arm projecting laterally from theupper end of said standard; a1 secondary wall projecting laterally from the inner standard wall and into the coniines of .said compartment and having a vertical `portion and a horizontal portion which form with said inner standardwall a chamber interiorly of said standard compartment, said vertical wall portion :being formed with a horizontally extending aperture, said horizontal wall portion kbeingformed with a depending member which extends downwardly into said compaatrneniL and has a vertically disposed and'downwardly progressively enlarged bore running lengthwise therethrough with its longitudinal axis horizontally spaced from that `of `said aperture; an .upper rotary shaft disposed within and lengthwise ofwsaid arm and having one end `portion thereof extending into said chamber and being journaled within said aperture; a driven wheel. gear carried by said upper shaft and disposed within said chamber adjacent the upper end of said bore; a unitary driving structure including an electric motor having a motor casing small enough to be vertically disposed within the lower portion of said compartment, ank elongated stem projecting axially in a progressively reduced manner from said casing and provided with a peripheral bearing surface complemental in size to thel internal wall of said bore but having its greatest lateral dimension substantially less than the smallest lateral dimensionhf the motor casing, an elongated motor shaft journaled within and projecting from the free end of said stem, and a driving work gear carried upon the distal end of said motor shaft, said driving structure normally beingy removably disposed within said compartment with its stem being slidingly received lengthwise of and within said bore; means removably to maintain said stem in a mating relation with said bore thereby to position said worm gear within said chamber and in mesh with said wheel gear; a lower rotary shaft journaled in and extending lengthwise of said base; and driving means disposed within said standard compartment and connec t ing said upper and lower shafts for rotationv in a fixed timing relationship, said lower shaft and said driving means being located entirely at one side of said motor casing so that the unitary driving structure may be inserted into and removed from said compartment by way of said base.v

6. A sewing machine comprising in combination aframe including a vhorizontally exten-ding hollowv base with a. vertically disposed hollow standard rising from one end portionof said base,

the innerwalls of said stan-dard and basatogether forming a vertically: disposed compartment which extends entirely through the bottom of said frame base, and an arm projecting laterally from the upper end of said standard; an upperrotary shaft journaled inland extending lengthwise of saidarm; adriven gear carried. by said: uppershaft over Vsaid compartment; a sec.- ondary'wall rprojecting fromthe inner standard walland into the confinesof `saidi compartment at `the junctionof said arm and standard, said secondary wall depending downwardlyfinto said compartment and havinga substantially vertically` disposed bore running lengthwise therethrough with the -lengthof said borebeing substantially greater in dimension than the greatest lateral diameter thereof; a unitary driving structureincluding an electric motor having amotor casing vertically disposed within the lower portion of said compartment, an elongated stem projecting axiallyfrorn said casing and provided with a peripheral bearing surface of electrical insulating material complemental in sizeto the internal wall of said bore with the length of said stern being `at least equal to one-half the axial length of the motor casingproper, an elongated motor shaft journaled within and projecting from the free endof said stem, and a driving gear carried upon thel distal end of said motor shaft, said driving structure normally being, removably disposed within said compartment with its stem being slidingly received lengthwise of and within said bore; means carriedv bysaid framefor maintaining said stem in axmating relation with said bore thereby to position said two gears in-,mesh, one of said two gears-being of `electrical insulating material so as to cooperate with said stem in insulating said driving structure from said frame; a lower rotary shaft journaled in and extending lengthwise-of said base; and driving means disposed within said standard compartment and connecting said upper and lower shafts for rotation in a xed timing relationship, said lower shaft and said drivingmeans being located entirely at one side of said motor casing so that the unitary structure may be inserted into and removed from said compartment byway of said base.

WILBUR J. PEETS.

REFERENCES CYTED The following references are of record inthe. le of this patent:

UNI'IED STATES PATENTS Number Name Date 1,394,320 Mace Oct. 18, 1921 1,417,676 Mace May 30, 1922 1,462,516 Mace July 24, 1923 1,852,807 Janssen Apr. 5, 1932 1,916,860 Hohmann July 4, 1933 1,934,373 Peets Nov. 7, 1933 1,962,880 Schwab et al June 12, 1934 1,975,744 Goosman Oct. 2, 1934 2,064,070 Mapes et al Dec. 15, 1936 2,130,802 Kisling Sept. 20, 1938 2,207,251 Guedon July'9, 1940 2,318,442 Way et al May 4, 1943 FOREIGN PATENTS Number Country Date 636,409 France Jan. l1, 1928 

